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light bulb savings calculations

these calculations display your estimated savings based on assumptions below

for customized calculations enter your own data in the green fields

Wattage
3.5 watts
Rated Lifetime
25,000 hours
price
$14.95
average incandescant (INC) light bulb
Wattage
watts
Rated Lifetime
hours
price

cost per kilowatt hour
bulb use per day hours

how your savings are calculated

step 1 find the number of INC bulbs needed over this bulb's lifetime

25000 / 750 = 33.3333

step 2 determine the cost of replacement INC bulbs and the difference with this bulb's cost

33.3333 * $0.50 = $16.67 cost of replacing the INC bulb

$16.67 - $14.95 = $1.72 replacement savings

step 3 determine energy usage over the life of this bulb

25 watts * 25000 hours / 1000 watts per kW = 625 kWh

3.5 watts * 25000 hours / 1000 watts per kW = 87.5 kWh

step 4 subtract to find the difference in energy usage between the bulbs

625 kWh - 87.5 kWh = 537.5 kWh lifetime savings

step 5 find the lifetime energy cost savings

537.5 kWh * $0.118 = $63.43

step 6 combine energy savings with replacement cost savings to find total lifetime savings

$63.43 + $1.72 = $65.14 total lifetime savings

step 7 find savings per year

5 hours per day * 365 days per year = 1825 hours per year

1825 hours per year / 25000 lifetime hours = 7.30 % of bulb life used per year

7.30 % * 537.5 kWh lifetime savings = 39.2375 kWh yearly savings

7.30 % * $65.14 lifetime savings = $4.76 yearly savings

Savings calculations are presented as an example of potential savings; actual savings may vary based on use, utility rates and other factors. Calculations are based on national averages and assumptions and may be adjusted for a more accurate estimate of individual savings. While EnergyEarth strives to provide the most accurate information, we cannot guarantee the savings displayed.